Process of making tight castings.



ROBERT B. WOLF, OF BERLIN, NEW HAMPSHIRE.

PROCESS OF MAKING TIGHT CAST'INGS.

1,214,630. Specification of Lette rs Patent. P t t d 6 19.17 No Drawing I Application filed Marchl4, 1914. Serial No. 822,378. I

Having thus explained my invention, what I claim is r 1. The herein described process of plugging metallic castings, which consists in subjecting said castings alternately to vacuum and pressure in the presence of an acid, and then filling the pores and interstices thereof With a sulfate insoluble in ,water.

2. The herein described process ct plugging metallic castings, which includes subjecting said castings to alternate pressure and vacuum in the presence of a pore-filling mineral salt insoluble in Water.

The herein described process of closing the pores and interstices of metallic castings, which. consists in exhausting the air from such pores and interstices and precipitating in the same a sulfate insoluble in water.

The herein described process of treating metallic castings, Which consists in cleaning the pores and interstices thereof with a suitable acid under conditions of alternating vacuum and pressure, and precipitating a mineral compound in pores and interstices.

esta es o 5. The herein described process of closing the pores and interstices of metallic cast ings, which consists in subjecting the casting's alternately to vacuum and pressure, and simultaneously precipitating in said pores and interstices a mineral compound insolu ble in Water.

6. The herein described process of closing the pores and interstices of metallic castings, Which consists in subjecting the castings alternately to vacuum and pressure, and simultaneously precipitating calcium sulfate in saidpores and interstices.

7. The herein described process of filling the pores of bronze castings which consists in cleaning the pores of said castings with sulfurous acid and subjecting said castings alternately to a vacuum and pressure in the presenceof calcium bisulfite liquor contain ing calcium sulfate in suspension.

in testimony whereof it have atlixed my signature, in presence of two Witnesses.

Roster n. Wont.

Witnesses JAMns F. SMITH, ALFRED ll. GILBERT. 

